Single processor system-single CPU-only ONE process can be run at a time-the other processes must wait until the CPU becomes free

Multiprocessor system-2 or more CPUs in a system and share common RAM-divide memory as many partitions as the CPUs-give each CPU its own private memory and its own private copy of the OS

Clustered system-allows 2 or more individual systems tied together and share the storage-closely linked via WLAN networking-uses multiple CPUs to complete a task-usually performed to provide high availability

Symmetric Clustering-2 or more machines run the applications-machines monitor each other at the same time-more efficient-used only when there is multiple applications are available to run

Various Type OS Structure

Monolithic-considered as "The Big Mess" because it is no structure actually-components are unorganized-any module can call any other module w/o any reservation-a collection of procedures-no information hiding

Layered-breaks the OS into different layers-allows implementers to change the inner workings and increases modularity-developers have more freedom to do so as long as the external interface of the routines don't change-bottom layer is hardware and the top layer is user interface-main difficulty: defining the various layers-main advantages: simplicity of construction and debugging-main disadvantages: OS tends to be less efficient

Microkernel-components in it communicate directly with one another-validate messages, passes them between the components and grant access to hardware-advantages -easier to extend -easier to port the OS to new architecture -more reliable(less code is running in kernel mode) -more secure(a server crashing in userspace)

Networked and Distributed-Network OS(NOS) is a software program that controls other software and hardware that runs on a network-allows multiple computers to communicate with one main computer and each other -to share resources, run applications, send messages among other things-a computer network can consist of a wireless network, LAN, WAN, or even 2 or 3 computer networks

Describe the following concept in relation of OS

Multitasking- concurrent or inserted execution of 2 or more jobs by a SINGLE CPU

Multiprogramming: a technique that allows a single processor to process multiple programs residing simultaneously in main memory

Time sharing: sharing of a computing resources among many users, allows a large number of users to interact concurrently with a single computer

Buffering: to copes with a speed mismatch between producer and consumer of a stream data

Spooling: an acronym for simultaneous peripheral operation on-line

Caching: save the recently accessed data at a temporary area to improve access time and reduces data traffic